An exceptional bathing-and-recovery experience with 100% free-flowing black bath water and a state-of-the-art sauna
Miyagi Osaki City
"Hare Onsen" is a day-use hot spring facility in Naruko Onsenkyo, Osaki City, Miyagi Prefecture, renovated from the former Matsubara Sanso. It prides itself on 100% free-flowing natural spring water with no heating, no added water, and no disinfection, featuring a black bath (moru spring) with a soft texture and abundant benefits. It also offers a state-of-the-art pellet sauna, where powerful heat from self-löyly and an intensely cold cold plunge bath using Naruko's pristine water make for an appealing hot-and-cold bathing experience. In the relaxation area equipped with infinity chairs, you can savor a blissful totonou while feeling the atmosphere of this historic hot spring town.
TypeNatural Hot Spring
A 100% free-flowing natural hot spring made by luxuriously blending two kinds of spring water. The moru spring (black bath) contains plant-derived organic components and is characterized by its distinctive aroma and soft feel on the skin. Because no heating, no added water, and no disinfection are ever performed, the pure spring components soak into the body, warming you from the core and leaving your skin astonishingly supple after bathing.
Sauna TypeDry Sauna
Stove TypeConvection Stove (Sauna Stone)
Capacity6people
A wood-warm dry sauna equipped with a state-of-the-art pellet stove. Self-löyly is available, so you can adjust the humidity and temperature to suit your preference and enjoy invigorating perspiration from powerful heat. The gentle warmth of the burning pellets and the rising steam softly envelop your whole body, guiding you into a deeply relaxed state. *Men's bath only (ladies' day held regularly)
Water QualityTap Water
Capacity2people
A chilled cold plunge bath using Naruko's pristine water. It instantly tightens your overheated body after the sauna and provides a refreshing cooldown. The water quality is very mellow and gentle on the skin. By alternating between the sauna and the cold bath, you can enjoy a revitalizing experience that sharpens both body and mind.
Closed Days: Thursday
42 Hisada, Naruko Onsen, Osaki City, Miyagi Prefecture 989-6711
Gender Access
Gender Separated
Curated by an expert who visits onsen and sauna facilities every day and has explored 300+ locations — only facilities confirmed to be truly exceptional are featured.
Learn more
An exceptional bathing-and-recovery experience with 100% free-flowing black bath water and a state-of-the-art sauna
Miyagi Osaki City
"Hare Onsen" is a day-use hot spring facility in Naruko Onsenkyo, Osaki City, Miyagi Prefecture, renovated from the former Matsubara Sanso. It prides itself on 100% free-flowing natural spring water with no heating, no added water, and no disinfection, featuring a black bath (moru spring) with a soft texture and abundant benefits. It also offers a state-of-the-art pellet sauna, where powerful heat from self-löyly and an intensely cold cold plunge bath using Naruko's pristine water make for an appealing hot-and-cold bathing experience. In the relaxation area equipped with infinity chairs, you can savor a blissful totonou while feeling the atmosphere of this historic hot spring town.
TypeNatural Hot Spring
A 100% free-flowing natural hot spring made by luxuriously blending two kinds of spring water. The moru spring (black bath) contains plant-derived organic components and is characterized by its distinctive aroma and soft feel on the skin. Because no heating, no added water, and no disinfection are ever performed, the pure spring components soak into the body, warming you from the core and leaving your skin astonishingly supple after bathing.
Sauna TypeDry Sauna
Stove TypeConvection Stove (Sauna Stone)
Capacity6people
A wood-warm dry sauna equipped with a state-of-the-art pellet stove. Self-löyly is available, so you can adjust the humidity and temperature to suit your preference and enjoy invigorating perspiration from powerful heat. The gentle warmth of the burning pellets and the rising steam softly envelop your whole body, guiding you into a deeply relaxed state. *Men's bath only (ladies' day held regularly)
Water QualityTap Water
Capacity2people
A chilled cold plunge bath using Naruko's pristine water. It instantly tightens your overheated body after the sauna and provides a refreshing cooldown. The water quality is very mellow and gentle on the skin. By alternating between the sauna and the cold bath, you can enjoy a revitalizing experience that sharpens both body and mind.
Closed Days: Thursday
42 Hisada, Naruko Onsen, Osaki City, Miyagi Prefecture 989-6711
Gender Access
Gender Separated
Curated by an expert who visits onsen and sauna facilities every day and has explored 300+ locations — only facilities confirmed to be truly exceptional are featured.
Learn more